If you’re feeling cranky, confused or too tired even for sex, blame it on Thomas Alva Edison. We’re all bushed, and it’s all his fault.

Humans have been screwing with their body clocks—and getting less sleep—ever since the Wizard of Menlo Park had his very bright idea. Indeed, our classic eight-hour-night only dates back to the invention of the light bulb in the late 1800s.